Research And Modification Of Lightning Protection Measure For Secondary Equipment In Center Building Of Electric Power Corporation In Yuan Ling

Lightning surge is one of the main causes of electrical equipment failures. In recent years, more and more equipment have been struck by the lightning. Compared to the previous lightning characteristics, current characteristics and the form of lightning show differently. A significant feature is that the low-voltage systems have been frequently struck by the lightning, which lead to people's lives and production suffered more and more losses. Nowadays, large amounts of researches about lightning surge have done in the country and abroad, but the specific research of lightning protection of secondary equipment is relatively small. Most researches focus on electromagnetic compatibility and algorithms of electromagnetic environment, but comprehensive lighting protection measures for the secondary equipment have not been paid enough attention.This paper summarizes the results on the basis of existing researches in the country and abroad. Firstly, several forms of lightning and the lightning surge intrusion are introduced, and mechanism of secondary equipment failure is analyzed in several ways. Secondly, based on the actual conditions of lightning damage to the secondary equipment in the building of Yuanling electrical power, a comprehensive lightning protection mode of secondary equipment is introduced by using distribution of current and voltage, equipotential bonding, grounding and shielding and other measures. This paper analyzes the impact of surge protection factors with the waveform, amplitude of current source, line parameters and load, and conducted two levels of surge protection by using PSCAD modeling and simulation, which lead to a conclusion that while the good using of the equipotential bonding and shielding can reduce the requirements of the grounding resistance.Two levels of surge protection and related mechanism of influencing factors are obtained by theoretical study and analysis of simulation result. While installing surge protectors at different places, different emphases should be considered to be the appropriate choice of economic devices. Lightning protection should be adapted to local conditions. Only in this way, can lightning protection of secondary equipment be safe and efficient.